High-level JCPyV replication is seen in less than 10% of patients after kidney transplantation. Patients who are JCPyV seronegative before transplantation seem to be at a higher risk of high-level JCPyV viruria after transplantation. High-level JCPyV viruria is not associated with inferior graft function or survival in long-term follow-up. High-level JCPyV viruria was not associated with histopathological changes in protocol biopsies.